Smetana was a guiding light behind the establishment of the National Theatre, which opened in 1883 with a performance of his opera Libuše. But although the building is almost sacred, performances are vital. The theatre concentrates on Czech opera, the core of the repertoire being works by Smetana and Dvořák (including lesser-known works such as Dvořák's The Devil and Kate). Operas by non-Czech composers and impressive ballets are also performed; there are generally five or six major new productions a year year.